A Systematic Approach towards the Integration of Initial Airworthiness Regulatory Requirements in Remotely Piloted Aircraft System Conceptual Design Methodologies
Abstract
:1. Introduction
1.1. Research Scope
1.2. Research Structure
2. Theoretical Background
2.1. Aircraft Design and Relation to Airworthiness
- Conceptual design: Starting from the initial requirements, a basic geometric definition of the Outer-Mold Line (OML) of the air vehicle is sought. Methods usually involve statistical approaches and rapid physical-based approaches, and only a few disciplines are considered;
- Preliminary design: Once the main layout and architecture of the aircraft is defined, the design is further refined by employing methods with a higher level of fidelity and usually employing a multidisciplinary approach involving optimisation procedures;
- Detailed design: Very specific aspects of the design are refined by employing methodologies with a high degree of fidelity and computational cost, such as Computational Fluid Dynamics (CFD) and Finite Element Method (FEM) analyses.
2.2. RPAS Initial Airworthiness and Operations Regulatory Paradigm Highlights
- Risk-based and operations-centric approach: The concept of developing regulations in accordance to the proportionality of risk of the object for which these rules are being developed is not new and has been present in manned aviation for a long time [41]. However, as the regulatory initiatives for RPASs have developed and matured, there has been a redirection from a traditional approach, which is “aircraft-centric”, to an “operation-centric” approach, based on an analysis of the risks resulting from the combined consideration of the aircraft and its operation—in line with previous research in this area [4]. In the framework of EASA, different operational categories (open, specific and certified) have been defined, where regulatory requirements increase in correlation with risk—from minimal regulatory oversight in the first case to a very similar model to manned aircraft in the third, in which initial airworthiness and operators are certified, amongst other aspects [42,43];
- Tight coupling between airworthiness and operational considerations: In relation to the previous point, one of the most innovative aspects of current RPAS regulations is that a very tight coupling between airworthiness and operation considerations can be seen, with aspects related to these areas often appearing side-to-side in the same regulations [8]. This is coherent with the risk-based approach, which considers aspects inherent to the aircraft in combination with those of the operational scenario, often with both aspects in combination determining the regulations that apply to the aircraft under consideration.
- Performance-based approach to airworthiness codes: The reorganisation and change in spirit of the Part/CS-23 regulations [44] has had a notable impact in the field of RPAS regulations. This activity sought to regulate through “objective oriented” requirements, seeking to provide flexibility to applicants in the way that they demonstrate compliance with the regulation specifications, and at the same time intending to reduce both regulatory time and costs, both for the industry and for the regulator [44]. In summary, and in relation with the previously mentioned concept of “level of specificity”, the requirements provided in the code have a lower level of specificity and are less prescriptive in nature. The applicant can opt to demonstrate compliance with them through use of Acceptable Means of Compliance (AMC) and Guidance Material (GM), which, in the case of the reorganisation of manned aircraft regulations, can include references to previous versions of the regulations and also to consensus standards. Through consulting these other references, a higher level of specificity can be achieved. This approach has been supported in the area of RPASs in works previous to its implementation, such as [17]. This concept has been implemented, for instance, in the CS-UAS by JARUS [45], where the specific requirements that the designer can find outside the main document are called Airworthiness Design Standards (ADS). However, contrary to the Part/CS-23 approach, there is no clear correspondence here between each requirement of the regulation and the corresponding ADS recognised by the Authority, which can be regarded as an additional challenge to establish the initial certification basis and to guarantee certifiability assurance in advance to making specific consultations with the Authority.
3. Literature Review and Research Gap Analysis
3.1. Previous Reviews of RPAS Regulatory Paradigm
3.2. Previous Works in Design and Initial Airworthiness Integration
3.3. Emerging Technologies in RPAS and Prospective Influences in Certification and Design
4. Materials and Methods
4.1. Criteria for the Review of Design-Related Airworthiness Regulations
- Level of Regulatory Document Tier (LRD Tier): Usually, regulators organise the taxonomy of their documents according to “levels of regulatory material”, such as EASA, which has a hierarchical structure of its regulations. For instance, the Basic Regulation is at a higher hierarchical position than the CS codes, and so on. In this work, documents from entities with differing criteria to organise their material are being studied. Therefore, the present LRD Tier concept is applied in a broader sense, allocating the same Tier to documents with a similar nature in their breadth and scope. Tier 1 is for high-level documents laying out essential requirements and covering a broad scope, including implementing regulations. At the same time, their level of depth and detail is usually low, as the intention is to provide general governing guidelines and not specific criteria. For example, the EASA Basic Regulations, in the Essential Requirements for Airworthiness, lay out general qualitative criteria for structures and materials; however, one must consult the lower-tier CS codes to find specific quantitative limit load factor values [29]. Tier 2 is for more detailed documents giving specific provisions for aspects that are not covered within Tier 1 ones, in the vein of Certification Specifications (e.g., Part/CS-23). Tier 3 documents have more detail and focus, such as FAA Advisory Circulars (ACs), and EASA AMC and GM. Tier 4 is reserved for consensus standards and similar documents.
- Legal applicability: Refers to the nature of the document with respect to its legally-binding status or otherwise. This dimension is not exclusively dependent on the document itself but also on the scope of application that is considered (countries affected by the legislation, civil/military paradigm). Within this work, this shall be evaluated within the main civil framework of each regulation. For instance, the legal applicability of FAA Part 107 is evaluated for the USA, whereas the legal applicability for EASA regulations is assessed for the EU Member States.
- Topical focus: Brief summary related to the main subjects covered by the document.
- Level of specificity: This concept was explained in Section 2.1. Three levels are considered: low, when only general qualitative criteria are given; medium, where no detailed quantitative specifications are provided but more specific aspects to be taken into account or calculated by the applicant are provided; and high, where specific values or limits are given. Within Appendix D, some examples are provided of excerpts of regulatory documents of RPASs corresponding to each of these levels in order to further illustrate the criteria employed within this dimension. From a design perspective, and in relation with the discussion of Section 2.1, requirements with a high level of specificity could be integrated in a more straightforward way within design methods as quantitative restrictions. On the other hand, those with a low or medium level of specificity could be integrated as qualitative criteria or can serve to highlight variables of interest to be defined within the design approach;
- Streamlined or ad-hoc requirements: Streamlined procedures are those that are relatively straightforward in that the requirements to comply with are mostly laid out in advance (such as in classical certification specification codes). However, in the field of RPASs, there are cases, mostly pertaining to specific category operations [43], where requirements or mitigations are laid out depending on the result of a prior operational risk assessment. An example is the Specific Operations Risk Assessment (SORA) methodology by JARUS, where the number of barriers, as well as their integrity, depend on the result of a prior operational risk assessment. In these cases, the requirements are a function of the outputs of this risk assessment study; therefore, depending on the case of application, the set of conditions that must be complied with are different. These are considered ad-hoc procedures, and they do not provide a pre-established certification basis; rather, it is dependent both on the aircraft and the operation to be conducted. From a design perspective, these approaches could hinder the integration of requirements within design methodologies due to various reasons: (a) as they are dependent on the operational scenario, different operations might demand differing requirements, and also not all operational scenarios might be envisioned in the first stages of the design project; (b) the safety assessment might demand analysis on certain aspects of the aircraft that might not be known at the first stages of the design, such as systems architecture or reliability estimations, which is in line with the reasons for the application of more advanced risk analysis techniques being usually left for later design stages, as commented in Section 2.1; (c) the case-by-case basis approach of determining the certification basis for each combination of aircraft and operational scenario can complicate the definition and integration of a unique set of certification aspects. There may be some alternative ways to conduct the safety evaluation by the Authority depending on the regulatory paradigm, such as acquiring a Light UAS Operator Certificate (LUC) in the EASA paradigm. However, these options would be outside the scope of this paper.
- Scope: Aircraft type (fixed-wing, rotary-wing) and operational category (open specific, certified).
4.2. RPAS Regulatory Document Search Process
- The search engines of the entities’ websites have been used with keywords related to the area of study, including, amongst others: ‘RPA’, ‘RPAS’, ‘UAV’, ‘UAS’, ‘drone’, ‘unmanned aircraft’, etc. The search results were then sorted so as to keep those related to the scope of the study;
5. Analysis of Regulations Regarding RPAS Initial Airworthiness and Operational Restrictions
5.1. Stage 1: Broad Review of Current Regulatory Landscape
5.1.1. ICAO
5.1.2. EU/EASA
- Commission IR 2019/947 [81]: Focuses on aspects related to rules and procedures for the operation of RPASs, laying out the principles for the three main categories of operations: open, specific and certified. It also covers topics such as remote pilot licensing and instructions related to conducting operational risk assessments for the specific category.
- Commission DR 2019/945 [82]: Deals with the applicable requirements for RPASs in the different categories of operations with respect to manufacturer’s obligations and markings and documentation for commercial RPASs. The Appendix expounds the specific limitations for the classes of RPASs from C0 to C6, mainly intended for open and specific operations.
- Commission DR 2024/1108 [83] and IR 2024/1110 [84]: These recently approved regulations integrate RPAS aspects within the classical framework of the EU Implementing Regulation for initial airworthiness IR 748/2012, allowing RPASs as well as their equipment and control stations to be included within the paradigm of type certificates, establishing the certification basis, airworthiness certificates, etc.
5.1.3. USA/FAA
- Part 107 [89]: This is the main regulation in the FAA paradigm for flying RPASs below 55lb with commercial and professional purposes and is also an option for public operations that fall within the restrictions of this regulation. It lays out requirements with respect to pilot licensing, operational restrictions, registration of aircraft, etc. Four different operational categories are established for operations over human beings, with differing requirements and restrictions with respect to the aircraft and operation characteristics. Waivers can be requested for many of the limitations, which are evaluated by the FAA on a case-by-case basis.
- 49 USC 44809 Exception for limited recreational operations of unmanned aircraft [90]: Provides a limited set of requirements for recreational activities of RPASs, being also the current area where model aircraft fall into. One of the main aspects is that the user must fly according to guidelines and safety standards of FAA-recognised Community-Based Organization (CBO). The AC 91-57C establishes guidelines with respect to these organisations and their required safety standards.
- 49 USC 44807 Special Authority for certain unmanned aircraft systems [91]: This approach is envisioned for RPAS operations presenting characteristics that are not an option for waiver through Part 107. Here, the applicant conducts a safety risk analysis, which is checked by the Administrator on a case-by-case basis, and measures are established according to the safety analysis results; therefore, it is an ad-hoc approach.
- In the case of public operations, one option is to fly under Part 107 if the aircraft and operation comply with their requirements. A second option is through a Certificate of Authorization (COA), which requires an application containing mainly operational information, which is reviewed by the FAA. A third option is provided through 49 USC 40102 (a) (41) or 49 USC 40125, which is intended for public aircraft operations. The latter two procedures are markedly ad-hoc and limited to public operations; thus, they are not included in the Table 1 evaluation.
- Certification of advanced operations: Another way for RPAS operations is to follow the traditional options to aircraft certification, including alternatives for special airworthiness certificates and flight permits. In the case of RPASs, as no specific codes are yet available, one of the recommended options is through an experimental airworthiness certificate employing the FAA Order 8130.34D for Airworthiness Certification of Unmanned Aircraft Systems and Optionally Piloted Aircraft [92]. However, it should be noted that this document is not a detailed airworthiness code; rather, it employs an approach consisting of an initial evaluation and the calculation of a risk index in order to determine the criteria with which the applicant has to comply and the level of the safety evaluation considered by the FAA, therefore being again markedly ad-hoc.
5.1.4. JARUS
5.1.5. NATO
- NATO Standard AEP-4671 [95]: This document consists of a very thorough and detailed code, with high level of specificity, based on that of the legacy CS-23, with additions in certain points related to RPAS-specific aspects. It is intended primarily for heavyweight fixed-wing RPASs.
- NATO Standard AEP-83 [96]: This code is focused on lightweight fixed-wing RPASs and is therefore associated with a lower risk of aircraft operations. It has a particular form not seen in other instances, where requirements are laid out in a table with three columns. The first column contains the high-level airworthiness essential requirements, the second one provides detailed arguments that add a layer of specificity upon the relatively broad guidelines of the first, and the third contains directions with respect to the means of evidence.
5.1.6. Overall Discussion and Conclusions of Stage 1 of the Survey
Entity | Regulation | LRD Tier | Legally Binding? | Topical Focus | Lvl. of Specificity | Streamlined or Ad-Hoc | Availability | Scope | |
---|---|---|---|---|---|---|---|---|---|
Aircraft Type | Operation Category | ||||||||
ICAO | Circular 328 [75] | Tier 1 | No | Varied | Low | Streamlined | Public | All | - |
RPAS Manual [76] | Tier 1 | No | Varied | Low | Streamlined | Public | All | - | |
Chicago Convention Annexes | Tier 1 | Yes a | Varied | Low-Medium | Streamlined | Payment required | All | Certified | |
Part 101 and 102 [79] | Main doc: Tier 1 ACs: Tier 3 | No | Operations | Medium | 101: Streamlined 102: Ad-hoc | Public | All | 101: Open 102: Specific | |
Part 149 [80] | Tier 1 | No | Organisation approvals | Low | Streamlined | Public | All | Open and specific | |
EASA | IR 2019/947 [81], DR 2019/945 [82] | Main doc: Tier 1 AMC and GMs: Tier 3 | Yes | Operations, design | Medium | Open category: Streamlined Specific category: ad-hoc | Public | All | All |
DR 2024/1108 [83], IR 2024/1110 [84] | Tier 1 | Yes | Initial airworthiness certification framework | Medium | Streamlined | Public | All | Specific and certified | |
SC-RPAS.SubpartB-01 [87] | Main doc: Tier 2 AMC and GMs: Tier 3 | No | Initial airworthiness, design | High | Streamlined | Public | Fixed wing | See footnote b | |
SC Light UAS [88] | Tier 2 | No | Initial airworthiness, design | Medium | Streamlined c | Public | All | Specific | |
FAA | USC 44809 [90] | Main doc: Tier 1 ACs: Tier 3 | Yes | Varied | Low-Medium | Depends on guidelines of organisation | Public | All | - |
Part 107 [89] | Tier 1 | Yes | Varied | Medium | Streamlined | Public | All | - | |
USC 44807 [91] | Tier 1 | Yes | Assessment of special operations | Low | Ad-hoc | Public | All | - | |
Order 8130.34D [92] | Tier 3 | No | Experimental certification process | Medium | Ah-hoc | Public | All | - | |
JARUS | CS-LUAS [93] | Main doc: Tier 2 AMC and GMs: Tier 3 | No | Initial airworthiness, design | High | Streamlined | Public | Fixed wing | Certified |
CS-UAS [45] | Main doc: Tier 2 AMC and GMs: Tier 3 | No | Initial airworthiness, design | Medium | Streamlined d | Public | All | Certified | |
SORA [94] | See footnote e | No | Risk assessment of operations | Medium-High | Ad-hoc | Public | All | Specific | |
NATO | AEP-4671 [95] | Main doc: Tier 2 AMC and GMs: Tier 3 | No f | Initial airworthiness, design | High | Streamlined | Public | Fixed wing | Certified |
AEP-83 [96] | Tier 2 and 3 | No f | Initial airworthiness, design | Medium-High | Streamlined | Public | Fixed wing (mainly) | Certified |
5.2. Stage 2: Design and Operational Applicability of Selected Documents
Entity | Regulation | Design Applicability | Operational Restrictions | ||||||
---|---|---|---|---|---|---|---|---|---|
Mass (MTOM) | Aircraft Type | Operation Category | Impact Energy | Max. Speed | Max. Height | Distance to Aerodromes | Proximity to People | ||
ICAO | Part 101 [79] | <25 kg a | All | Open | - | - | <120 m AGL | >4 km | >30 m |
EASA | Subcategory A1 [81] | C0: <0.25 kg C1: <0.9 kg b | C0, C1: electric powered | Open | C1: <80 J terminal velocity | C0, C1: <19 m/s | <120 m AGL c | See note d | No overflight of assemblies |
Subcategory A2 [81] | C2: <4 kg | Electric powered | Open | - | - | <120 m AGLc | See note d | >30 m | |
Subcategory A3 [81] | C2: <4 kg C3, C4: <25 kg b | All | Open | - | - | <120 m AGL c | See note d | >150 m | |
SC-RPAS. SubpartB-01 [87] | See note e | Fixed-wing | See note f | Unpremeditated descent: <0.003 MJ, LOC: <0.02 MJ | - | - | - | - | |
SC Light UAS [88] | See note g | All | Specific | See note g | See note g | See note g | See note g | See note g | |
FAA | Part 107 [89] | <25 kg | All | - | See note h | <44.8 m/s | <122 m AGL c | See note i | Generally no overflying e |
JARUS | CS-LUAS [93] | <750 kg | Fixed wing | Certified | - | - | - | - | - |
CS-UAS [45] | Non-VTOL: <8618 kg VTOL: <3175 kg | All | Certified | - | - | - | - | - | |
NATO | AEP-4671 [95] | Mainly 150–20,000 kg | Fixed wing | Certified | - | - | - | - | - |
AEP-83 [96] | <150 kg | Fixed wing | Certified | >66 J j | - | - | - | - |
6. Flexible Procedure for Design Criteria Extraction (DECEX)
6.1. Rationale for the Development of the DECEX Procedure
- Firstly, the designer requires a common reference of all the potential applicable regulations, the requirements of which might be extracted. Albeit in the field of manned aviation the potential regulations are clearer and well-established; in this case, as seen in the aforementioned sections, the material is more spread out. It could be said that this point has been tackled, at least within the scope of this work, through the survey conducted beforehand in this paper.
- There is a notable heterogeneity not only in the main characteristics of the regulations as evaluated with the criteria proposed in Section 4.1, but also in their content related to specific topics (such as the definitions and requirements with respect to airspeeds, as commented in Section 5.2), which is in contrast with the comparatively more homogeneous manned aviation paradigm.
- There is a general lack of publicly available high-specificity regulations and standards for the certified category of RPASs. As commented in Section 2.1, detailed provisions are the ones that can be most easily integrated in quantitative procedures, and they also provide larger certifiability confidence.
- Adding to the above issues, even if detailed consensus standards were accessible to complement low-specificity requirements in the main texts, there are no detailed directions for the correspondence of the requirements in the main regulation with the applicable standards to demonstrate compliance with that particular requirement.
- As seen before, the RPAS regulatory paradigm is very dynamic. Therefore, design approaches that are not flexible and cannot easily adapt to changes in the regulations through the integration of new requirements could risk becoming obsolete in a few years.
6.2. DECEX Application Workflow
- As the objective is to integrate airworthiness aspects within a design methodology or process, the first stage, in accordance with the theoretical background commented in Section 2.1, is to establish the topical scope of the design activity. This mainly includes the design stage of interest and potential disciplines of consideration.
- Then, a search is conducted to find the main applicable regulatory documents, accounting for the aforementioned scope. It should be noted that the survey conducted in Section 5 can constitute this step for design activities mainly related with the RPA airframe and dealing with early design stages. If the scope is different, other documents can be reviewed here for integration in the procedure. If the regulations change, this step can be modified to integrate the new applicable documents, in order to update the design approach according to the novel regulations by following the procedure from here.
- At this point, and in view of the documents that have been reviewed, the ones applicable to the design methodology scope are selected for the next stages. This will also be dependent on the category of operations associated to the expected output design and the operational scenario. Table 1 and Table 2 provided in this work can be consulted for this stage. Only those documents that are applicable continue on the next step.
- In the next steps, the corpus of documents from which regulatory requirements will be extracted shall be selected, with different priority levels depending on the degree of correspondence to the scope of the design activity. The main idea behind this is to have, aside from the main ones, other documents to attend to in case the foremost ones have a low level of specificity such that it is preferred to seek clearer and quantitative requirements in others, and also to compare the restrictions set by the different ones. This process of selecting alternative regulatory documents to use when the main ones do not achieve the desired characteristics, or to complete their gaps with requirements from others, has been used in previous works [37,40] within the manned aviation paradigm to great effect. Firstly, those documents that are directly aligned in applicability (as in the results of stage 2 of the survey in Section 5.2) to the scope of the design activity, are labelled as “Main documents” along with their AMC and GM.
- Having selected the main documents, and as the issue of low level of specificity is widespread in the field of RPAS regulations, as it was seen in the review, a second group of documents is selected. These will be those that are explicitly referred to in the main documents, which can serve as ADS or complimentary material to the main ones. For instance, CS-UAS explicitly recommends the use of CS-LUAS as ADS for cases where the latter is applicable within the CS-UAS paradigm. It has been noted in Section 5.1.6 that the correspondence between main documents and their ADS is seldom stated in a direct way in the field of RPASs, which complicates this step, and this is the reason for considering a third group of documents.
- The third group of documents are potential documents that, even if not directly applicable to the design case, are other reputable references that may aid in filling the gaps from the first and second groups. For instance, if the RPA is being designed within the civil domain, military RPAS regulations can be considered here or even manned aviation documents applicable to a similar MTOM range. Even outside the design process, upon seeking approval by the Authority of the certification basis, these other documents can be useful to seek for alternative and more detailed proof of compliance approaches for those points in which the applicable main documents are not detailed. All of this generates a corpus of documents where the potential specificity gaps of the primary ones can be covered by the secondary and tertiary references.
- For the next step, it is necessary to define with more detail the relevant variables related to design aspects that are related to the scope of the methodology: geometric, performance, structural, etc. Specific variables should be defined, such as climb gradient, stall speed, obstacle height for Take-Off, etc. This will serve for the next step, where specific requirements will be sought within the documents in relation to the design aspects of interest.
- Now, having both the corpus of documents and the regulatory documents of the three levels, the next step consists of examining each of those references for the applicable requirements for each design variable of interest. These are compiled in a table, as seen in Figure 5, in such a way that for each variable, the applicable aspects from each document are compiled. At this point, the specificity would be evaluated at requirement level, instead of for the whole document, which was anticipated in Section 4.1 when defining the level of specificity criterion. Furthermore, this allows a direct comparison of the similarity and differences in the content of the requirements, allowing to detect, for instance, heterogeneous limit values for certain restrictions.
- Once the table has been crafted, the level of specificity for each variable is evaluated for the group of documents. If any gaps are identified, for instance no high level of specificity requirement having been found for certain variable, more regulatory material can be sought to achieve the desired level. Once the results are satisfactory, the next step is undertaken.
- Considering the results from the table, these are translated to the design methodology in one of two forms. For those variables for which a high level of specificity has been found, the requirement can enter the design activity as a quantitative constraint in the relevant equations or in the optimisation process. Those variables for which this condition is not achieved are not discarded; rather, they can also be integrated as qualitative criteria. For instance, a requirement such as “the aeroplane should present desirable stability and control characteristics”, even if not providing a quantitative limit, can be taken into account so the designer can generate objective values attending to this criterion, or as a general design guideline.
6.3. Example Application Cases
6.3.1. Case Study 1: Tactical RPA
6.3.2. Case Study 2: HALE RPA
7. Conclusions
- The definition of the criteria proposed in this paper in Section 4.1 to scrutinise the regulations, which consider both airworthiness and design–integration aspects.
- The up-to-date survey, considering both design and airworthiness characteristics, which has been conducted on the international paradigm of RPAS initial airworthiness, having analysed some documents that are particularly recent and, thus, were not considered in previous works.
- The synthesis of DECEX: a flexible, adaptable and systematic approach for the integration of airworthiness aspects in design, which is broadly applicable to design approaches with different scopes, allowing to populate them with relevant certification considerations.
- The procedure provides a streamlined way to compare the similarities and differences amongst regulatory requirements from different regulations within the scope of the design method, as it was demonstrated particularly in the second case study when contrasting conditions and values for climb gradient were found.
- It allows users to solve specificity gaps in main regulations by evaluating other, more detailed regulations from different entities and aviation paradigms. This was demonstrated particularly in case study 1, where a limit value for rate of climb was found in SC-RPAS.SubpartB-01 and CS-VLA, whereas the other regulations provided no explicit restrictions.
- Its flexibility allows to populate design methodologies that have different scopes with regulatory requirements from diverse regulations. This was seen through the two case studies, each for a different category of RPA (tactical and HALE), thus resulting in distinct regulations to be considered.
- It enables contrasting the effect of airworthiness restrictions on the design space when compared to the case of only considering initial specification requirements. In both case studies, the design space is reduced when considering certifiability, albeit the impact of airworthiness aspects was different in each of them.
- The characteristics of flexibility and adaptability of DECEX allow it to be applied to a variety of regulatory landscapes and design methodology scopes, which is a necessity in the field of RPASs due to the aforementioned heterogeneity in regulations, the fact that rulemaking is still in progress and regulations are to be updated, and the novel design concepts that are usually developed in this area.
Author Contributions
Funding
Data Availability Statement
Acknowledgments
Conflicts of Interest
Abbreviations
AAM | Advanced Air Mobility |
AC | Advisory Circular |
ADS | Airworthiness Design Standard |
AGL | Above Ground Level |
AI | Artificial Intelligence |
AMC | Acceptable Means of Compliance |
ASTM | American Society for Testing and Materials |
ATC | Air Traffic Control |
ATM | Air Traffic Management |
CBO | Community-Based Organization |
CFD | Computational Fluid Dynamics |
CFR | Code of Federal Regulations |
COA | Certificate of Authorization |
CONOPS | Concept of Operations |
CS | Certification Specification |
DAA | Detect And Avoid |
DECEX | DEsign Criteria EXtraction |
DR | Delegated Regulation |
EASA | European Union Aviation Safety Agency |
EU | European Union |
EUROCAE | European Organisation for Civil Aviation Equipment |
FAA | Federal Aviation Administration |
FEM | Finite Element Methods |
GM | Guidance Material |
HALE | High-Altitude Long Endurance |
ICAO | International Civil Aviation Organization |
IR | Implementing Regulation |
ISO | International Organization for Standardization |
JAA | Joint Aviation Authorities |
JARUS | Joint Authorities for Rulemaking of Unmanned Systems |
LRD | Level of Regulatory Document |
LG | Landing Gear |
LUC | Light UAS Operator Certificate |
MALE | Medium-Altitude Long Endurance |
MDO | Multidisciplinary Design Optimisation |
MTOM | Maximum Take-Off Mass |
NAA | National Aviation Authority |
NPA | Notice of Proposed Amendment |
NATO | North Atlantic Treaty Organization |
OML | Outer-Mold Line |
RA | Resolution Advisories |
RPA | Remotely Piloted Aircraft |
RPAS | Remotely Piloted Aircraft System |
RTA | Run-Time Assurance |
SARP | Standard and Recommended Practice |
SC | Special Condition |
SORA | Specific Operations Risk Assessment |
TCA | Time of Closest Approach |
ToR | Terms of Reference |
UAS | Unmanned Aircraft Systems |
UAV | Unmanned Air Vehicle |
USA | United States of America |
USC | United States Code |
VLA | Very Light Aircraft |
Appendix A. Table of Overview of Literature References from RPASs’ Four Main Dimensions towards Safe Integration in the Aviation Paradigm
Reference | Year | Topical Dimensions | Scope | Analysed Characteristics and Parameters | Limitations |
---|---|---|---|---|---|
Dalamagkidis et al. [7] | 2008 |
| International RPAS regulations landscape and RPAS rulemaking characteristics and perspectives | Evaluation of manned aviation airworthiness aspects and discussion of possible applicability and adaptations for rulemaking of RPASs. Parameters include RPAS mass and flight altitude, expected fatalities in case of accident, etc. | Scope mainly focused on prospective regulatory aspects, as the RPAS regulatory paradigm was incipient by that time |
Cuerno-Rejado, Martínez-Val [6] | 2011 |
| Analysis of international initial airworthiness regulatory landscape and evaluation of applicability in existing RPA | Evaluation of airworthiness code applicability through a case study focused on load requirements. Parameters include impact kinetic energy, lethal crash area, gust load factor, etc. | Case study scope limited to manned aircraft code tailoring to RPASs according to EASA Policy E.Y013-01 |
Cook [9] | 2018 |
| Identification and discussion of main trends in airworthiness regulations of RPASs | Evaluation of aspects related to safety targets, influence of CONOPS in regulations and implementation of aspects such as DAA and AI. Parameters include safety probability objectives, RPA MTOM, etc. | Scope focused on the five overall trends of airworthiness regulations identified in the paper |
Stöcker et al. [10] | 2018 |
| Global overview of worldwide national RPAS regulations, including evaluation and comparison of pilot qualifications | Analysis of statements and requirements on technical, operational and pilot licensing requirements from different regulations. Parameters include year of regulation release, regulation weight limits, requirements of competency and/or licensing depending on aircraft mass and operation characteristics, etc. | Regulatory information limited to those provided by secondary regulation databases. Consideration of political and social acceptance aspects outside the scope of the paper |
Massuti and Tomasello [8] | 2018 |
| International airworthiness and operations regulations for RPASs. Legal basis for personnel qualification, pilot requirements and operator responsibility | RPAS classifications towards regulatory applicability. Personnel requirements and considerations in different paradigms and operation categories. Parameters include safety probability objectives, RPA MTOM, pilot age, required tests, medical requirements, etc. | Scope mainly covers ICAO, EASA and FAA paradigms, with a few specific countries such as Italy. Military regulations outside the scope of the work |
Karyotakis et al. [3] | 2021 |
| Safety assessment and assurance of advanced and specific operations of RPASs, considering ATM aspects | Influences of ATC, pilot and air vehicle in safety analysis results. Two types of operations: transport of people and of goods. Parameters include RPAS accident rate, ground risk, RPA weight, SORA SAIL level, etc. | Scope focused on specific category of operations. Open and certified categories fall outside of the scope of the research |
Ferreria et al. [11] | 2018 |
| Risk analysis of integration of RPASs in non-segregated airspace, considering ATM, C2 link and security aspects amongst others | Quantitative risk analysis of two hazardous scenarios: mid-air collision and ground collision. Parameters include C2 link reliability, initial and residual risk of hazards, conflict probability, etc. | Model limited to remotely piloted aircraft, without conventional aircraft in the airspace. Design aspects and reliability of other systems from C2 link outside the scope of the paper |
Pérez-Castán et al. [5] | 2020 |
| Challenges of RPAS integration in non-segregated airspace attending to traffic volume and conflict simulations | Analysis of air conflicts in an example airspace zone attending to the number of RPA. Parameters include number of conflicts, conflict duration, No. of RPASs, etc. | Model limited to one flight level with no climb or descent manoeuvres |
Stroeve et al. [12] | 2023 |
| ACAS Xu simulations of RPASs evaluating loss of separation considering response of remote pilot | Definition of model of remote pilot considering stochastic variations in pilot and aircraft aspects. Parameters include remote pilot response delay, strength, mode, stochastic models of onboard sensors and communication systems, etc., with output metrics such as TCA and RA percentages | Simplified encounter geometry only two aircraft, straight original trajectories with short duration when compared to ACAS validation studies |
Peukert et al. [13] | 2024 |
| Development of traffic display system for RPAS pilots towards improving traffic avoidance | Evaluation of existing traffic display models and responses of RPAS pilots to novel questionnaire. Parameters include display units, conflict depiction, symbols for display elements, etc. | No experimental comparison of implemented display effectiveness compared to previous alternatives |
Janke and de Haag [14] | 2022 |
| Survey of status quo of adoption of new EU regulations within Member States in terms of operators and registration | Analysis of number of Remote Pilot licences within the current framework of the EU. Parameters include no. of A1/A3 licences per country, no. of LUC per country, no. of operators per country, etc. | Missing data from certain Authorities that did not respond to the survey. Data on individual aircraft unavailable |
Maier et al. [15] | 2024 |
| Proposal of new RPAS pilot training plan for RPA of high MTOM | Crew requirements and training plan for rotary wing RPASs of high MTOM. Parameters include required flight hours, licence test manoeuvres, training requirements and periodicity, etc. | Scope limited to the development of a pilot training plan for a specific rotary wing RPASs |
Appendix B. Table of Literature Review Evaluation of Surveys and Analyses on RPAS Regulations
Reference | Year | Regulatory Focus | Topical Focus | Analysed Characteristics and Parameters |
---|---|---|---|---|
Dalamagkidis et al. [7] | 2008 | Main international RPAS framework and certain National regulations | Rulemaking activities, airworthiness certificates and RPAS classifications | Possible classifications of RPASs towards certification and potential regulatory road map. Parameters include RPAS mass and flight altitude, minimum time between ground impact accidents, etc. |
Cuerno-Rejado, Martínez-Val [6] | 2011 | International civil and military regulations: EASA, FAA and others | Airworthiness and design: focus on impact energy and load requirements | Practical evaluation of applicability of manned aircraft codes using impact energy criterion. Parameters include impact kinetic energy, gust load factor, structural weight, etc. |
Valavanis, Vachtsevanos [17] | 2015 | EU National RPAS regulations | Technical and operational requirements | Comparison of restrictions to evaluate harmonisation challenges and perspectives. Parameters include MTOW limitations and LOS conditions per regulation, number of operators and manufacturers per region, etc. |
Stöcker et al. [10] | 2017 | Worldwide National RPAS regulations | Technical, operational and administrative requirements | Applicability and main limitations of regulations within selected topics. Parameters include MTOW limitations, distance to aerodromes, distance to people, LOS conditions, etc. |
Masutti and Tomasello [8] | 2018 | International civil regulations, mainly ICAO, EASA and FAA | Varied topics: airworthiness, security, personnel licensing, etc. | Air Law perspective. Scope of regulations, main topics, applicability, etc. Parameters include MTOW limitations, mission radius, probability of failure, etc. |
Bassi [16] | 2019 | EU/EASA civil framework | Privacy, cybersecurity and remote identification | Air Law perspective. Competences of the organisations and open issues. Parameters include regulations and articles related with security, liability, privacy, remote identification, etc. |
Srivastava et al. [18] | 2020 | Worldwide National RPAS regulations | Operations, registration, licensing, data protection and privacy | Operational restrictions and requirements with respect to the analysed topics. Parameters include MTOM limitations, maximum height, lateral distance, etc. |
Xu et al. [46] | 2020 | Worldwide National RPAS regulations | Operations, airspace design and ATM for low altitude operations | Operational restrictions, ATM technologies and airspace architectures. Parameters include maximum flight height, geo-fencing volume characteristics, etc. |
Karyotakis et al. [3] | 2021 | EU and FAA civil paradigms for advanced operations | Airspace integration and ATM for RPASs in relation to specific operations | Comparison of the requirements for advanced/specific operations in both frameworks. Parameters include RPAS mass and height, maximum dimension of RPA, impact kinetic energy, etc. |
Alamouri et al. [47] | 2021 | EU/EASA civil regulations | Rulemaking activities, technical properties, operational prospects and risk assessment approach | Operational category applicability and application of the SORA methodology. Impact of regulations on RPAS use and economic potential. Parameters include RPAS mass and height, maximum dimension of RPA, ground risk class, etc. |
Janke, de Haag [14] | 2022 | EU/EASA civil framework | Personnel licensing and RPAS registration | Requirements towards personnel licensing and registration marks for operation categories. Parameters include EASA open subcategories, no. of operators for specific operations, etc. |
This research | 2024 | International civil and military regulations: ICAO, EASA, FAA, JARUS, NATO | Airworthiness aspects related to aircraft (conceptual) design | Airworthiness aspects and design considerations affecting the potential integration and influence of requirements in design methods. Parameters include document regulatory tier, topical focus of regulations, level of specificity *, scope, RPA MTOM, etc. |
Appendix C. Table of Literature Review Evaluation of Previous Research on Airworthiness and Design Integration
Reference | Aircraft Type | Design Stage Focus | Research Scope | Airworthiness Regulations and Integration in Design Activities |
---|---|---|---|---|
Torenbeek [19] | Manned | Conceptual and preliminary: rapid, low-fidelity methods | Full concept synthesis and initial sizing of subsonic aircraft. Encompassing design approach covering performance, aerodynamics, structures, stability and control, powerplant aspects, etc. | Integration of FAA and CAA regulations in many aspects and sizing procedures. For instance, requirements for performance in matching diagram, structural requirements in manoeuvring envelope, stability and control requirements for tail sizing, etc. |
Roskam [25] | Manned | Conceptual and preliminary: rapid, low-fidelity methods | Full concept synthesis and initial sizing of civil and military aircraft. Encompassing design approach covering performance, aerodynamics, structures, stability and control, powerplant aspects, etc. | Integration of FAA regulations and certain military standards in many aspects and sizing procedures. For instance, requirements for performance in marching diagram, cabin layout, stability and control requirements for tail sizing, etc. |
Stinton [36] | Manned | Conceptual and preliminary: rapid, low-fidelity methods | Full concept synthesis and initial sizing of aircraft, with a focus on light aircraft. Encompassing design approach covering performance, aerodynamics, structures, stability and control, powerplant aspects, etc. | Various considerations: FAA, JAA and CAA certification categories and applicability ranges; analysis of main paragraphs regarding flying qualities and performance; evaluation of impact in design areas and relation with relevant variables; limits for pilot effort when sizing control surfaces, etc. |
Tyan et al. [37] | Manned | Conceptual and preliminary: rapid methods and optimisation | Initial OML layout sizing and optimisation of general aviation aircraft attending to regulatory requirements | FAR 23 and KAS 23 regulations. Dedicated procedure for elaboration of certification database and requirement extraction. Consideration of variable constraints attending to regulatory restrictions within optimisation procedure and final compliance check |
Nöding and Bertsch [48] | Manned | Preliminary: simulation framework with multiple disciplinary modules | Evaluation of transport aircraft noise in relation to take-off and approach trajectories and design parameters, such as fuselage geometry and MTOM. Sensitivity studies evaluating contributions of engines and airframe | Aircraft noise metrics as well as take-off and approach trajectories according to ICAO Annex 16 regulations are evaluated for the design concepts analysed with the simulation framework |
Spencer [49] | Manned | Preliminary: systems architecture, engineering and safety | Evaluation of current airworthiness codes limitations towards certifying hydrogen-fuelled aeroplanes, considering the main aspects of hydrogen power systems | Analysis of current CS-25 certification requirements affecting the propulsion system (crashworthiness, explosion prevention, etc.) and discussion on gaps in their application to the certification basis and design of hydrogen aeroplanes |
Schmollgruber et al. [26] | Manned | Conceptual and Preliminary: MDO framework | Development of a dedicated certification module within the design package FAST. The module allows to manage the certification constraints established by the regulations and their integration in an MDO process | The certification module allows a formal representation of the relationships between CS-25 regulatory requirements and key design variables in UML format, standardising their representation and integration into design MDO workflows as optimisation constraints |
Xie et al. [50] | Manned | Preliminary: MDO framework | Proposal of a certification-driven environment for the integration of certification constraints in multi-objective airframe optimisations. Case study of horizontal tail refinement attending to flight mechanics requirements | The flight characteristics module checks, for the input aircraft geometry, a series of characteristics extracted from the regulations, mainly requirements from CS 25 Subpart B and Subpart C to check both flight mechanics and structural compliance |
Travascio et al. [40] | Manned | Preliminary: systems engineering | Once a system architecture for a disruptive concept such as a hybrid propulsion system) has been defined, a procedure is proposed to identify certification basis gaps from existing regulations in order to propose modifications or introduction of new requirements through a safety assessment process | Regulations such as CS-25, CS-E and CS-P are analysed for potential requirements considering the system architecture of study. The gaps in the requirements are covered by generating a proposal of means of compliance that are obtained through a safety assessment of the system design |
Jeyaraj et al. [51] | Manned | Preliminary: systems engineering and MDO | Development of a methodology to introduce safety assessment earlier in the design continuum, focusing on system architecture and safety analysis, towards seamless integration in MDO approaches | Regulatory requirements for systems, such as those of Part 23 or Part 25 (as stated in an application example), are included through a safety filtering method that analyses proposed architectures and keeps those that comply with the requirements |
Insley and Turkoglu [52] | Manned | Not applicable | Analysis of commercial air transport accidents and serious incidents related to maintenance, supplemented with opinions gathered from experts, in order to identify main factors and high-risk areas | No regulatory requirement integration in design methodologies |
Habib and Turkoglu [53] | Manned | Not applicable | Study of general and commercial aviation accidents and serious incidents in the context of Nigeria, complemented with a survey from subject matter experts, to identify root causes and main areas of concern | No regulatory requirement integration in design methodologies |
Rötger et al. [54] | Manned | Not applicable | Review of current regulations applicable to supersonic transport aircraft and current rulemaking activities. Discussion on prospective regulatory aspects to be covered in future rules | No regulatory requirement integration in design methodologies |
Kusmierek et al. [55] | Manned | Not applicable | Survey of opportunities and challenges of hybrid propulsion systems considering the demands of emission regulations and objectives. Evaluation of different system architectures and trends of aircraft equipped with these powertrains | No regulatory requirement integration in design methodologies |
Sóbester et al. [24] | RPASs | Conceptual and preliminary | Development of a geometry service to produce and modify both the OML and the structural layout of RPA. Evaluation of weight, wing loading and power loading trends for RPA | No regulatory requirement integration in design methodologies |
Gundlach [21] | RPASs | Conceptual and preliminary: rapid, low-fidelity methods | Full concept synthesis and initial sizing of RPASs. Covers many aspects of RPAS design, not only including those of the air vehicle: aerodynamics, performance, structures, powerplant aspects, payload and communications, command and control, etc. | As the regulatory framework of RPASs was still incipient, the regulatory considerations considered in the method have mainly been adapted from manned aircraft regulations |
Keane et al. [33] | RPASs | Conceptual, preliminary and detailed design | Full coverage of the different stages of RPAS design, mainly focused on small RPA. Conceptual design methods are mainly focused on rapid approaches such as the matching diagram, preliminary methods usually employ optimisation, and detailed design aspects are mainly focused on final geometry definition for manufacturing | The relevance of integrating airworthiness aspects in RPA design is supported, and the main structure and contents of NATO Standard AEP-83 are explained, recommending checking various typical design constraints towards certification |
Gómez-Rodríguez et al. [22] | RPASs | Conceptual: statistical approach | Evaluation of main design trends of H-tail RPA by employing factor analysis on an RPA database. Development of a rapid sizing method based on the results of the factor analysis approach | No regulatory requirement integration in design methodologies |
Gómez-Rodríguez et al. [56] | RPASs | Conceptual: statistical approach | Analysis of a database of RPASs, evaluating general design trends with respect to layout and powerplant, and development of a rapid sizing method for H-tail RPA based on correlations obtained from the database | Thresholds for MTOM towards design trend analysis established in part attending to regulations at the time of research; however, some of these are no longer applicable |
Mitridis et al. [57] | RPASs | Conceptual: statistical approach | Analysis of a database of RPAS attending to the NATO classification, analysing key categorisation aspects and design parameters through correlations, dot plots and box plots | No regulatory requirement integration in design methodologies |
Champasak et al. [35] | RPASs | Preliminary: multiobjective optimisation | Development of a metaheuristic-based optimisation framework for RPA design incorporating reliability aspects. Four case applications are conducted based on pre-defined value ranges for optimisation variables | No regulatory requirement for integration in design methodologies |
Tyan et al. [58] | RPASs | Conceptual and preliminary: rapid, low-fidelity methods and optimisation | Initial sizing of a hybrid fixed-wing VTOL small RPA using rapid sizing procedures and a matching diagram constraint approach. Further optimisation and resizing of the vehicle starting from the initial concept | Maximum flight height of Part 107 regulations is considered as the cruising altitude of the RPA |
Aliaga-Aguilar and Cuerno- Rejado [59] | RPASs | Conceptual and preliminary: rapid methods towards integration in MDO | Development of aerodynamic and performance modules towards their integration within an MDO-driven computerised design environment for small RPA | No regulatory requirement integration in design methodologies |
Torrigiani et al. [27] | RPASs | Preliminary: MDO framework with multiple disciplinary modules | Starting from an initial MALE RPA concept, it is optimised through the use of the AGILE framework comprising multiple modules, from geometry definition to aerodynamic calculations including systems engineering | Consideration of CS-25 regulatory requirements, particularly particular lightning protection, with respect to systems engineering in the requirements definition and optimisation process, accounting for systems interaction |
Casarosa et al. [28] | RPASs | Conceptual: rapid weight estimation method | Analysis of RPAS onboard system requirements and trends towards developing a rapid weight estimation method for the take-off weight of a certifiable RPA. Use of statistical data of onboard equipment to develop the estimation approach | Definition of the minimum equipment required and redundancies attending to airworthiness design requirements available for civil RPASs at the time of publication, particularly safety targets. This information is employed to estimate the required equipment and, from the statistical data, the weight |
Cuerno-Rejado and Martínez- Val [6] | RPASs | Conceptual: rapid, low-fidelity methods | Development of a rapid approach towards estimating RPA required structural weight to withstand gust and manoeuvre loads prescribed by applicable regulations. Evaluation in a case study of various existing RPA to compare the structural weight required to comply with the regulations with the actual one | Considering the EASA Policy E.Y013-01, which allows to derive requirements for RPA through the tailoring of manned aviation certification codes, the corresponding applicable codes are obtained for various existing RPA, and from the requirements, for each of them, the gust and manoeuvring requirements are derived |
Appendix D. Level of Specificity Examples
Appendix D.1. Low Level of Specificity
Appendix D.2. Medium Level of Specificity
Appendix D.3. High Level of Specificity
References
- Available online: https://ec.europa.eu/docsroom/documents/19184?locale=en (accessed on 6 September 2023).
- Gertler, J.; Zoretich, T. 2022/2023 World Civil Unmanned Aerial Systems Market Profile & Forecast; Market report; Teal Group Corporation: Fairfax, VA, USA, 2023. [Google Scholar]
- Karyotakis, M.; Panagiotakopoulos, D.; Braithwaite, G.; Tsourdos, A. Aspects and Challenges of Unmanned Aircraft Systems Safety Assurance and Certification for Advanced Operations. In Proceedings of the AIAA Aviation 2021 Forum, Virtual Event, 2–6 August 2021. AIAA 2021-2397. [Google Scholar] [CrossRef]
- Clothier, R.; Palmer, J.; Walker, R.; Fulton, N. Definition of an airworthiness certification framework for civil unmanned aircraft systems. Saf. Sci. 2011, 49, 871–885. [Google Scholar] [CrossRef]
- Pérez-Castán, J.; Gómez-Comendador, F.; Rodríguez-Sanz, A.; Valdés, R.A.; Alonso-Alarcón, J. Safe RPAS integration in non-segregated airspace. Aircr. Eng. Aerosp. Technol. 2020, 92, 801–806. [Google Scholar] [CrossRef]
- Cuerno-Rejado, C.; Martínez-Val, R. Unmanned Aircraft Systems in the Civil Airworthiness Regulatory Frame A case study. J. Aircr. 2011, 48, 1351–1359. [Google Scholar] [CrossRef]
- Dalamagkidis, K.; Valavanis, K.P.L. A Survey of Unmanned Aircraft Systems Regulation Status and Future Perspectives. In Proceedings of the 16th Mediterranean Conference on Control and Automation, Ajaccio, France, 25–27 June 2008. [Google Scholar] [CrossRef]
- Masutti, A.; Tomasello, F. International Regulation of Non-Military Drones; Edward Elgar Publishing Limited: Chentelham, UK, 2018; ISBN 978-1-78536-757-1. [Google Scholar]
- Cook, S.P.; King, L. Trends in Remotely Piloted Aircraft Systems Airworthiness. In Proceedings of the 2018 AIAA Information Systems-AIAA Infotech @ Aerospace, Kissimmee, FL, USA, 8–12 January 2018. AIAA 2018-1723. [Google Scholar] [CrossRef]
- Stöcker, C.; Bennett, R.; Nex, F.; Gerke, M.; Zevenbergen, J. Review of the Current State of UAV Regulations. Remote Sens. 2017, 9, 459. [Google Scholar] [CrossRef]
- Ferreira, R.; Baum, D.; Neto, E.P.; Martins, M.; Almeida, J.; Cugnasca, P.; Camargo, J. A Risk Analysis of Unmanned Aircraft Systems (UAS) Integration into non-Segregate Airspace. In Proceedings of the 2018 International Conference on Unmanned Aircraft Systems (ICUAS), Dallas, TX, USA, 12–15 June 2018; pp. 42–51. [Google Scholar] [CrossRef]
- Stroeve, S.; Villanueva-Cañizares, C.J.; Dean, G. Remote pilot modelling for evaluation of ACAS Xu. In Proceedings of the SESAR Innovation Days 2023, Seville, Spain, 27–30 November 2023. [Google Scholar]
- Peukert, M.; Santel, C. Tactical Conflict Avoidance of Manned Traffic-Display Concepts for UAV Pilots. CEAS Aeronaut. J. 2024, 15, 315–324. [Google Scholar] [CrossRef]
- Janke, C.; de Haag, M. Implementation of European Drone Regulations-Status Quo and Assessment. J. Intell. Robot. Syst. 2022, 106, 33. [Google Scholar] [CrossRef]
- Maier, L.; Hosseini, S.; Sax, F.; Rhein, J.; Barth, A.; Holzapfel, F.; Hajek, M.; Yavrucuk, I. Evaluation of the Pilot Training Concept for Flying a Helicopter UAV. In Proceedings of the AIAA SCITECH 2024 Forum, Orlando, FL, USA, 8–12 January 2024. AIAA 2024-1720. [Google Scholar] [CrossRef]
- Bassi, E. European Drones Regulation: Today’s Legal Challenges. In Proceedings of the International Conference on Unmanned Aircraft Systems (ICUAS 2019), Atlanta, USA, 11–14 June 2019; pp. 435–442. [Google Scholar] [CrossRef]
- Valavanis, K.P.; Vachtsevanos, G. Handbook of Unmanned Aerial Vehicles; Springer: Dordrecht, The Netherlands, 2015; ISBN 978-90-481-9706-4. [Google Scholar]
- Srivastava, S.; Gupta, S.; Dikshit, O.; Nair, S. A Review of UAV Regulations and Policies in India. In Proceedings of the 1st International Conference on Unmanned Aerial System in Geomatics (UASG 2019), Roorkee, India, 6–7 April 2019; pp. 315–325. [Google Scholar]
- Torenbeek, E. Synthesis of Subsonic Airplane Design; Kluwer Academic Publishers: Dordrecht, The Netherlands, 1982; ISBN 978-90-481-8273-2. [Google Scholar]
- Gudmundsson, S. General Aviation Aircraft Design, 1st ed.; Butterworth-Heinemann: Oxford, UK, 2014; ISBN 978-0-12-397308-8. [Google Scholar]
- Gundlach, J. Designing Unmanned Aircraft Systems: A Comprehensive Approach, 1st ed.; American Institute of Aeronautics and Astronautics (AIAA): Reston, VA, USA, 2012; ISBN 978-1-60086-843-6. [Google Scholar]
- Gómez-Rodríguez, A.; Sanchez-Carmona, A.; García-Hernández, L.; Cuerno-Rejado, C. Remotely Piloted Aircraft Systems Conceptual Design based on Factor Analysis. Aerosp. Sci. Technol. 2019, 90, 368–387. [Google Scholar] [CrossRef]
- Karakoc, T.H.; Özbek, E. Unmanned Aerial Vehicle Design and Technology; Springer Nature: Cham, Switzerland, 2024; ISBN 978-3-031-45320-5. [Google Scholar]
- Sóbester, A.; Keane, A.; Scanlan, J.; Bressloff, N. Conceptual design of UAV airframes using a generic geometry service. In Proceedings of the Infotech @ Aerospace Conferences, Arlington, VA, USA, 26–29 September 2005. AIAA 2005-7079. [Google Scholar] [CrossRef]
- Roskam, J. Airplane Design; Parts I–VIII; Design, Analysis and Research Corporation (DARcorporation): Lawrence, KS, USA, 1985; ISBN 978-1-884885-42-6/43-3/56-3/53-2/50-1/52-5/54-9/2-42. [Google Scholar]
- Schmollgruber, P.; Bartoli, N.; Bedouet, J.; Defoort, S.; Gourinat, Y.; Benard, E.; Lafage, R.; Sgueglia, A. Use of a certification constraints module for aircraft design activities (FAST). In Proceedings of the 17th AIAA Aviation Technology Integration, and Operations Conference, Denver, CO, USA, 5–9 June 2017. AIAA 2017-3762. [Google Scholar] [CrossRef]
- Torrigiani, F.; Deinert, S.; Fioriti, M.; Fede, F.D.; Jungo, A.; Pisu, L.; Sanchez, F.; Liscouet-Hanke, S.; Ciampa, P.; Nagel, B. MBSE certification-driven design of a UAV MALE configuration in the AGILE 4.0 design environment. In Proceedings of the AIAA Aviation 2021 Forum, Virtual Event, 2–6 August 2021. AIAA 2021-3080. [Google Scholar] [CrossRef]
- Casarosa, C.; Galatolo, R.; Mengali, G.; Quarta, A. Impact of safety requirements on the weight of civil unmanned aerial vehicles. Aircr. Eng. Aerosp. Technol. 2004, 76, 600–606. [Google Scholar] [CrossRef]
- Cuerno Rejado, C. Aeronavegabilidad y Certificación de Aeronaves, 1st ed.; Ediciones Paraninfo: Madrid, Spain, 2008; ISBN 978-84-2833-183-8. [Google Scholar]
- Pittini, M.; Kourousis, K. Harmonising and standardising military airworthiness in Europe: A review of key aspects and achievements. Aeronaut. J. 2023, 128, 911–927. [Google Scholar] [CrossRef]
- Gómez-Rodríguez, Á. On the Certification Aspects of RPAS and Their Relation with Design Strategies. Master’s Thesis, Cranfield University, Bedford, UK, 2024. [Google Scholar]
- Torenbeek, E. Advanced Aircraft Design: Conceptual Design, Analysis and Optimization of Subsonic Civil Airplanes; John Wiley & Sons Ltd: Chichester, UK, 2013; ISBN 978-11-1856-811-8. [Google Scholar]
- Keane, A.; Sóbester, A.; Scanlan, J. Small Unmanned Fixed-Wing Aircraft Design; John Wiley & Sons Ltd.: Chichester, UK, 2017; ISBN 978-11-1940-629-7. [Google Scholar]
- Gómez-Rodríguez, A.; Sanchez-Carmona, A.; García-Hernández, L.; Cuerno-Rejado, C. Assessment of aircraft conceptual design tools towards the synthesis of Remotely Piloted Aircraft platforms. In Proceedings of the 8th European Conference for Aeronautics and Space Sciences (EUCASS), Madrid, Spain, 1–4 July 2019. [Google Scholar]
- Champasak, P.; Panagant, N.; Pholdee, N.; Vio, G.; Bureerat, S.; Yildiz, B.; Yildiz, A. Aircraft conceptual design using metaheuristic-based reliability optimisation. Aerosp. Sci. Technol. 2022, 129, 107803. [Google Scholar] [CrossRef]
- Stinton, D. The Design of the Airplane, 2nd ed.; AIAA: Reston, VA, USA, 2001; ISBN 978-1-56347-514-6. [Google Scholar]
- Tyan, M.; Yoon, J.; Nguyen, N.V.; Lee, J.W.; Kim, S. Design-airworthiness integration method for general aviation aircraft during early development stage. Aircr. Eng. Aerosp. Technol. 2019, 91, 1067–1076. [Google Scholar] [CrossRef]
- Bleu-Laine, M.H.; Bendarkar, M.; Xie, J.; Briceno, S.; Mavris, D. A Model-Based System Engineering Approach to Normal Category Airplane Airworthiness Certification. In Proceedings of the AIAA Aviation 2019 Forum, Dallas, TX, USA, 17–21 June 2019. AIAA 2019-3344. [Google Scholar] [CrossRef]
- Nicolosi, F.; Marco, A.D.; Vecchia, P.D. Stability, flying qualities and longitudinal parameter estimation of a twin-engine CS-23 certified light aircraft. Aerosp. Sci. Technol. 2013, 24, 226–240. [Google Scholar] [CrossRef]
- Travascio, L.; Buzzo, G.; Pascarella, D.; Baldizzone, M.; Gily, M.; Casagrande, C.; Martina, V.; Quarona, E. Disruptive Technologies Certification Standard Approach. Aerospace 2023, 10, 637. [Google Scholar] [CrossRef]
- International Civil Aviation Organization. Good Regulatory Practices. 2016. Available online: https://www.icao.int/sustainability/Pages/regulatory_practices.aspx (accessed on 27 July 2024).
- European Union Aviation Safety Agency (EASA). Concept of Operations for Drones. A Risk Based Approach to Regulation of Unmanned Aircraft; Brochure; EASA: Cologne, Germany, 2015; Available online: https://www.easa.europa.eu/en/document-library/general-publications/concept-operations-drones (accessed on 27 July 2024).
- Joint Authorities for Rulemaking on Unmanned Systems (JARUS). UAS Operational Categorization. Document Identifier: Jar-del-wg7-uasoc-d.04, JARUS. 2019. Available online: http://jarus-rpas.org/wp-content/uploads/2023/06/jar_10_doc_UAS_Operational_Cat.pdf (accessed on 27 July 2024).
- Federal Aviation Administration (FAA); Department of Transportation (DOT). Revision of Airworthiness Standards for Normal, Utility, Acrobatic, and Commuter Category Airplanes. 81 fr 96572, Federal Register, USA. 2016. Available online: https://www.federalregister.gov/d/2016-30246 (accessed on 27 July 2024).
- Joint Authorities for Rulemaking on Unmanned Systems (JARUS). CS-UAS. Document Identifier: Jarus-del-wg3- cs-uas-d.04, JARUS. 2019. Available online: http://67.217.59.217/jarus/wp-content/uploads/2023/06/jar_13_doc_CS_UAS-1.pdf (accessed on 27 July 2024).
- Xu, C.; Liao, X.; Tan, J.; Ye, H.; Lu, H. Recent Research Progress of Unmanned Aerial Vehicle Regulations Policies and Technologies in Urban Low Altitude. IEEE Access 2020, 8, 74175–74194. [Google Scholar] [CrossRef]
- Alamouri, A.; Lampert, A.; Gerke, M. An Exploratory Investigation of UAS Regulations in Europe and the Impact on Effective Use and Economic Potential. Drones 2021, 5, 63. [Google Scholar] [CrossRef]
- Nöding, M.; Bertsch, L. Application of noise certification regulations within conceptual aircraft design. Aerospace 2021, 8, 210. [Google Scholar] [CrossRef]
- Spencer, R. Certification considerations for the configuration of a hydrogen-fuelled aeroplane. Aeronaut. J. 2023, 127, 213–231. [Google Scholar] [CrossRef]
- Xie, J.; Sarojini, D.; Cai, Y.; Corman, J.; Mavris, D. Certification-Driven Platform for Multidisciplinary Design Space Exploration in Airframe Preliminary Design. J. Aircr. 2022, 59, 329–349. [Google Scholar] [CrossRef]
- Jeyaraj, A.K.; Liscouët-Hanke, S. A Safety-Focused System Architecting Framework for the Conceptual Design of Aircraft Systems. Aerospace 2022, 9, 791. [Google Scholar] [CrossRef]
- Insley, J.; Turkoglu, C. A Contemporary Analysis of Aircraft Maintenance-Related Accidents and Serious Incidents. Aerospace 2020, 7, 81. [Google Scholar] [CrossRef]
- Habib, K.A.; Turkoglu, C. Analysis of Aircraft Maintenance Related Accidents and Serious Incidents in Nigeria. Aerospace 2020, 7, 178. [Google Scholar] [CrossRef]
- Rötger, T.; Eyers, C.; Fusaro, R. A Review of the Current Regulatory Framework for Supersonic Civil Aircraft: Noise and Emissions Regulations. Aerospace 2024, 11, 19. [Google Scholar] [CrossRef]
- Kuśmierek, A.; Galiński, C.; Stalewski, W. Review of the hybrid gas-electric aircraft propulsion systems versus alternative systems. Prog. Aerosp. Sci. 2023, 141, 100925. [Google Scholar] [CrossRef]
- Gómez-Rodríguez, A.; Sanchez-Carmona, A.; García-Hernández, L.; Cuerno-Rejado, C. Preliminary Correlations for Remotely Piloted Aircraft Systems Sizing. Aerospace 2018, 5, 5. [Google Scholar] [CrossRef]
- Mitridis, D.; Kapsalis, S.; Terzis, D.; Panagiotou, P. An Evaluation of Fixed-Wing Unmanned Aerial Vehicle Trends and Correlations with Respect to NATO Classification, Region, EIS Date and Operational Specifications. Aerospace 2023, 10, 382. [Google Scholar] [CrossRef]
- Tyan, M.; Nguyen, N.V.; Kim, S.; Lee, J.L. Comprehensive preliminary sizing; resizing method for a fixed wing- VTOL electric UAV. Aerosp. Sci. Technol. 2017, 71, 30–41. [Google Scholar] [CrossRef]
- Aliaga-Aguilar, H.; Cuerno-Rejado, C. Development and validation of software for rapid performance estimation of RPAS. Adv. Eng. Softw. 2017, 110, 1–13. [Google Scholar] [CrossRef]
- Clothier, R.A.; Williams, B.P.; Coyne, J.; Wade, M.; Washington, A. Challenges to the Development of an Airworthiness Regulatory Framework for Unmanned Aircraft Systems. In Proceedings of the 16th Australian Aerospace Congress (AIAC16), Melbourne, Australia, 23–24 February 2016; pp. 87–98, ISBN 978-92-9231-751-5. [Google Scholar]
- Banafaa, M.; Pepeoglu, Ö.; Shayea, I.; Alhammadi, A.; Shamsan, Z.A.; Muneef, A.R.; Alsagabi, M.; Al-Sowayan, A.S. A Comprehensive Survey on 5G-and-Beyond Networks with UAVs: Applications, Emerging Technologies, Regulatory Aspects, Research Trends and Challenges. IEEE Access 2024, 12, 7786–7826. [Google Scholar] [CrossRef]
- European Union Aviation Safety Agency (EASA). EASA Artificial Intelligence Roadmap 2.0: A Human-Centric Approach to AI in Aviation; EASA: Cologne, Germany, 2023; Available online: https://www.easa.europa.eu/en/document-library/general-publications/easa-artificial-intelligence-roadmap-20 (accessed on 30 August 2024).
- Costello, D.; Adams, R. A Framework for Airworthiness Certification of Autonomous Systems within United States Naval Aviation. J. Aviat. 2023, 7, 7–16. [Google Scholar] [CrossRef]
- Matalonga, S.; Black, J.; Riordan, J. Verification and Validation for a Digital Twin for Augmenting Current SORA Practices with Air-to-Air Collision Hazards Prediction from Small Uncooperative Flying Objects. J. Intell. Robot. Syst. 2024, 110, 109. [Google Scholar] [CrossRef]
- Nawaz, S.A. Regulating Autonomy in Civilian Drones: Towards a Spectral Approach. J. Intell. Robot. Syst. 2024, 110, 46. [Google Scholar] [CrossRef]
- Angelov, P. Sense and Avoid in UAS: Research and Applications; Wiley: Chichester, UK, 2012; ISBN 978-0-470-97975-4. [Google Scholar]
- Aibin, M.; Aldiab, M.; Bhavsar, R.; Lodhra, J.; Reyes, M.; Rezaeian, F.; Saczuk, E.; Taer, M.; Taer, M. Survey of RPAS Autonomous Control Systems Using Artificial Intelligence. IEEE Access 2021, 9, 167580–167591. [Google Scholar] [CrossRef]
- Ravi, A.K.; Olivares, G.; Gomez, L.; Bhasin, A.; Roberson, M.; Huberty, W.; Bounds, C. A53 A11L.UAS.93 Advanced Materials and Processes Survey for AAM and UAS Aircraft; Report; Alliance for System Safety of UAS through Research Excellence (ASSURE): Starkville, MS, USA, 2022. [Google Scholar]
- Battaglia, M.; Acanfora, V.; Garofano, A.; Maisto, G.; Riccio, A. An innovative approach to a UAV tails structural design for additive manufacturing. Polym. Compos. 2024, 45, 11149–11161. [Google Scholar] [CrossRef]
- Mieloszyk, J.; Tarnowski, A.; Goetzendorf-Grabowski, T. Designing aerodynamic devices for UAV-lessons learned. Aircr. Eng. Aerosp. Technol. 2024, 96, 73–83. [Google Scholar] [CrossRef]
- Mieloszyk, J.; Tarnowski, A.; Kowalik, M.; Perz, R.; Rzadkowski, W. Preliminary design of 3D printed fittings for UAV. Aircr. Eng. Aerosp. Technol. 2019, 91, 756–760. [Google Scholar] [CrossRef]
- Elelwi, M.; Pinto, F.S.; Botez, R.M.; Dao, T.-M. Multidisciplinary Optimization for Weight Saving in a Variable Tapered Span-Morphing Wing Using Composite Materials—Application to the UAS-S4. Actuators 2022, 11, 121. [Google Scholar] [CrossRef]
- Song, J.; Yan, J.; Yi, B. Design, fabrication, and characterization of hierarchical mechanical metamaterials. Front. Mech. Eng. 2024, 19, 3. [Google Scholar] [CrossRef]
- De Florio, F. An Introduction to Aircraft Certification and Operations, 3rd ed.; Butterworth-Heinemann: Saint Louis, MO, USA, 2016; p. 552. ISBN 978-00-8100-888-1. [Google Scholar]
- International Civil Aviation Organization (ICAO). Circular 328. Unmanned Aircraft Systems (UAS); Circular; ICAO: Montréal, QC, Canada, 2011; Available online: https://www.icao.int/Meetings/UAS/Documents/Circular%20328_en.pdf (accessed on 27 July 2024)ISBN 978-92-9231-751-5.
- International Civil Aviation Organization (ICAO). Manual on Remotely Piloted Aircraft Systems (RPAS), 1st ed.; Manual; Doc 10019; ICAO: Montréal, QC, Canada, 2015. [Google Scholar]
- International Civil Aviation Organization (ICAO). State Letter AN 11/61-22/70. Proposed New Annex 6, Part IV, and Consequential Amendments to Annexes 1, 2 and 8 Related to International Remotely Piloted Aircraft Systems (RPAS) Operations in Controlled Airspace/Aerodromes Arising from the Eighteenth Meeting of the Remotely Piloted Aircraft Systems Panel (RPASP/18); State letter; ICAO: Montréal, QC, Canada, 2022. [Google Scholar]
- International Civil Aviation Organization (ICAO). The ICAO UAS Toolkit; Web resources; ICAO: Montréal, QC, Canada, 2024; Available online: https://www.icao.int/safety/UA/UASToolkit/Pages/default.aspx (accessed on 27 July 2024).
- International Civil Aviation Organization (ICAO). ICAO Model UAS Regulations: Part 101 and Part 102; Model Regulations; ICAO: Montréal, QC, Canada, 2020; Available online: https://www.icao.int/safety/UA/Documents/Model%20UAS%20Regulations%20-%20Parts%20101%20and%20102.pdf (accessed on 28 July 2024).
- International Civil Aviation Organization (ICAO). ICAO Model UAS Regulations: Part 149; Model Regulations; ICAO: Montréal, QC, Canada, 2020; Available online: https://www.icao.int/safety/UA/Documents/Model%20UAS%20Regulations%20-%20Part%20149.pdf (accessed on 28 July 2024).
- European Union (EU). Commission Implementing Regulation (EU) 2019/947 of 24 May 2019 on the Rules and Procedures for the Operation of Unmanned Aircraft. Oj l 152, 11.6.2019, pp. 45–71, Official Journal of the European Union. 2019. Available online: http://data.europa.eu/eli/reg_impl/2019/947/oj (accessed on 27 July 2024).
- European Union (EU). Commission Delegated Regulation (EU) 2019/945 of 12 March 2019 on Unmanned Aircraft Systems and on Third-Country Operators of Unmanned Aircraft Systems. Oj l 152, 11.6.2019, pp. 1–40, Official Journal of the European Union. 2019. Available online: http://data.europa.eu/eli/reg_del/2019/945/oj (accessed on 27 July 2024).
- European Union (EU). Commission Delegated Regulation (EU) 2024/1108 of 13 March 2024 Amending Regulation (EU) No 748/2012 as Regards the Initial Airworthiness of Unmanned Aircraft Systems Subject to Certification and Delegated Regulation (EU) 2019/945 as Regards Unmanned Aircraft Systems and Third-Country Operators of Unmanned Aircraft Systems. Oj l, 2024/1108, 23.5.2024, Official Journal of the European Union. 2024. Available online: http://data.europa.eu/eli/reg_del/2024/1108/oj (accessed on 27 July 2024).
- European Union (EU). Commission Implementing Regulation (EU) 2024/1110 of 10 April 2024 Amending Regulation (EU) No 748/2012 as Regards the Initial Airworthiness of Unmanned Aircraft Systems Subject to Certification and Implementing Regulation (EU) 2019/947 as Regards the Rules and Procedures for the Operation of Unmanned Aircraft. Oj l, 2024/1110, 23.5.2024, Official Journal of the European Union. 2024. Available online: http://data.europa.eu/eli/reg_impl/2024/1110/oj (accessed on 27 July 2024).
- European Union Aviation Safety Agency (EASA). Terms of Reference for Rulemaking Task RMT.0230. Introduction of a Regulatory Framework for the Operation of Unmanned Aircraft Systems and for Urban Air Mobility in the European Union Aviation System, Issue 4; Tor rmt.0230–issue 4; EASA: Cologne, Germany, 2024; Available online: https://www.easa.europa.eu/en/document-library/terms-of-reference-and-rulemaking-group-compositions/tor-rmt0230 (accessed on 27 July 2024).
- European Union Aviation Safety Agency (EASA). EASA Concept Paper: Certified Category Operations of UAS, Certification of UAS and UAM Operations, Issue 2.1; Concept paper; EASA: Cologne, Germany, 2019. [Google Scholar]
- European Union Aviation Safety Agency (EASA). Proposed Special Condition RPAS.SubpartB-01, RPAS Subpart B–Fligh; Doc. no.: Sc-rpas.subpartb-01; EASA: Cologne, Germany, 2016; Available online: https://www.easa.europa.eu/en/document-library/product-certification-consultations/proposed-special-condition-rpassubpartb-01 (accessed on 27 July 2024).
- European Union Aviation Safety Agency (EASA). Special Condition Light UAS; Special Condition; EASA: Cologne, Germany, 2020; Available online: https://www.easa.europa.eu/en/document-library/product-certification-consultations/special-condition-light-uas (accessed on 27 July 2024).
- Federal Aviation Administration (FAA); Department of Transportation (DOT). 14 CFR Part 107. Code of Federal Regulations, 81 FR 42209. Regulation, Federal Register, USA. 2016. Available online: https://www.ecfr.gov/current/title-14/part-107 (accessed on 27 July 2024).
- United States Code (USC). 49 USC 44807: Special Authority for Certain Unmanned Aircraft Systems. Regulation, USA. 2019. Available online: https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title49-section44807&num=0&edition=prelim (accessed on 27 July 2024).
- United States Code (USC). 49 USC 44809: Exception for Limited Recreational Operations of Unmanned Aircraft. Regulation, USA. 2019. Available online: https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title49-section44809&num=0&edition=prelim (accessed on 27 July 2024).
- Federal Aviation Administration (FAA). Order 8130.34D-Airworthiness Certification of Unmanned Aircraft Systems and Optionally Piloted Aircraft; Faa order; FAA: Washington, DC, USA, 2017. [Google Scholar]
- Joint Authorities for Rulemaking on Unmanned Systems (JARUS). CS-LUAS. Document Identifier: Jar_del_wg3_d.04, JARUS. 2017. Available online: http://jarus-rpas.org/wp-content/uploads/2023/06/jar_07_doc_CS_LUAS.pdf (accessed on 28 July 2024).
- Joint Authorities for Rulemaking on Unmanned Systems (JARUS). JARUS Guidelines on Specific Operations Risk Assessment (SORA) v2.5 package. Document Identifier: Jar-del-srm-sora-mb-2.5, JARUS. 2024. Available online: http://jarus-rpas.org/wp-content/uploads/2024/06/SORA-v2.5-Main-Body-Release-JAR_doc_25.pdf (accessed on 28 July 2024).
- NATO Standard AEP-4671; Unmanned Aircraft Systems Airworthiness Requirements (USAR). Edition b version 1. NATO: Brussels, Belgium, 2019.
- NATO Standard AEP-83; Light Unmanned Aircraft Systems Airworthiness Requirements. Edition b version 1. NATO: Brussels, Belgium, 2016.
- F2910-22; Standard Specification for Design and Construction of a Small Unmanned Aircraft System (sUAS). ASTM: West Conshohocken, PA, USA, 2022.
- F3298-19; Standard Specification for Design, Construction, and Verification of Lightweight Unmanned Aircraft Systems (UAS). ASTM: West Conshohocken, PA, USA, 2019.
- F3563-22; Standard Specification for Design and Construction of Large Fixed Wing Unmanned Aircraft Systems. ASTM: West Conshohocken, PA, USA, 2022.
- ISO 21384-2:2021; Unmanned Aircraft Systems Part 2: UAS Components. ISO: Geneva, Switzerland, 2021.
- ISO 21384-3:2023; Unmanned Aircraft Systems Part 3: Operational Procedures. ISO: Geneva, Switzerland, 2023.
- Goetzendorf-Grabowski, T.; Rodzewicz, M. Design of UAV for photogrammetric mission in Antarctic area. Proc. Inst. Mech. Eng. Part G J. Aerosp. Eng. 2016, 231, 1660–1675. [Google Scholar] [CrossRef]
- Pranoto, F.; Budiyanta, A.; Prabowo, G. Small to Medium UAVs for Civilian Applications in Indonesia, 2nd ed.; IntechOpen Limited: London, UK, 2018; pp. 9–28. ISBN 978-1-78923-284-4. [Google Scholar]
- Rodzewicz, M.; Goraj, Z.; Tomaszewski, A. Design and testing of three tailless unmanned aerial vehicle configurations built for surveillance in Antarctic environment. Proc. Inst. Mech. Eng. Part G J. Aerosp. Eng. 2018, 232, 2598–2614. [Google Scholar] [CrossRef]
Code | Stall Speed (Vso) | Climb Gradient | Rate of Climb (Va) | Load Factor nlim+ | Gust Intensity Uc |
---|---|---|---|---|---|
CS-UAS | 2110: M | 2120: M | 2120: M | N/A (refers to ADS) | N/A (refers to ADS) |
CS-LUAS | N/A | 53: M a | N/A | 337: nlim+ ≥ 3.8 | 333: 15.24 m/s |
SC-RPAS. SubpartB-01 | 49: M | N/A | 65: ≥2 m/s | N/A | N/A |
AEP-4671 | 49: M | 65: ≥5% | N/A | 337: nlim+ ≥ 3.8 | 333: ≥15.24 m/s |
CS-VLA | 49: Vso ≤ 83 km/h | N/A | 65: ≥2 m/s | 337: nlim+ ≥ 3.8 | 333: 15.24 m/s |
Code | Climb Gradient (LG Retracted) | Climb Gradient (LG Extended) | Load Factor nlim+ | Gust Intensity Uc |
---|---|---|---|---|
AEP-4671 | 65: ≥5% | 65: ≥2.5% | 337: nlim+ ≥ 2.72 a | 333: ≥10.29 m/s b |
Part/CS-25 | See note c | 119: ≥3.2% d | 337: nlim+ ≥ 2.72 a | See note e |
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Gómez-Rodríguez, Á.; Turkoglu, C.; Cuerno-Rejado, C. A Systematic Approach towards the Integration of Initial Airworthiness Regulatory Requirements in Remotely Piloted Aircraft System Conceptual Design Methodologies. Aerospace 2024, 11, 735. https://doi.org/10.3390/aerospace11090735
Gómez-Rodríguez Á, Turkoglu C, Cuerno-Rejado C. A Systematic Approach towards the Integration of Initial Airworthiness Regulatory Requirements in Remotely Piloted Aircraft System Conceptual Design Methodologies. Aerospace. 2024; 11(9):735. https://doi.org/10.3390/aerospace11090735
Chicago/Turabian StyleGómez-Rodríguez, Álvaro, Cengiz Turkoglu, and Cristina Cuerno-Rejado. 2024. "A Systematic Approach towards the Integration of Initial Airworthiness Regulatory Requirements in Remotely Piloted Aircraft System Conceptual Design Methodologies" Aerospace 11, no. 9: 735. https://doi.org/10.3390/aerospace11090735